NOTICE: This opinion is subject to formal revision before publication in the
preliminary print of the United States Reports. Readers are requested to
notify the Reporter of Decisions, Supreme Court of the United States, Wash ington, D.C. 20543, of any typographical or other formal errors, in order that
corrections may be made before the preliminary print goes to press.

on writ of certiorari to the united states court
of appeals for the fifth circuit

[January 25, 1993]

Chief Justice Rehnquist delivered the opinion of the
Court.

Petitioner Leonel Torres Herrera was convicted of
capital murder and sentenced to death in January 1982.
He unsuccessfully challenged the conviction on direct
appeal and state collateral proceedings in the Texas state
courts, and in a federal habeas petition. In February
1992--10 years after his conviction--he urged in a second
federal habeas petition that he was "actually innocent" of
the murder for which he was sentenced to death, and that
the Eighth Amendment's prohibition against cruel and
unusual punishment and the Fourteenth Amendment's
guarantee of due process of law therefore forbid his
execution. He supported this claim with affidavits tending
to show that his now dead brother, rather than he, had
been the perpetrator of the crime. Petitioner urges us to
hold that this showing of innocence entitles him to relief
in this federal habeas proceeding. We hold that it does
not.

Shortly before 11 p.m. on an evening in late September
1981, the body of Texas Department of Public Safety
Officer David Rucker was found by a passerby on a
stretch of highway about six miles east of Los Fresnos,

Texas, a few miles north of Brownsville in the Rio Grande
Valley. Rucker's body was lying beside his patrol car. He
had been shot in the head.

At about the same time, Los Fresnos Police Officer
Enrique Carrisalez observed a speeding vehicle traveling
west towards Los Fresnos, away from the place where
Rucker's body had been found, along the same road.
Carrisalez, who was accompanied in his patrol car by
Enrique Hernandez, turned on his flashing red lights and
pursued the speeding vehicle. After the car had stopped
briefly at a red light, it signaled that it would pull over
and did so. The patrol car pulled up behind it. Carrisalez took a flashlight and walked toward the car of the
speeder. The driver opened his door and exchanged a few
words with Carrisalez before firing at least one shot at
Carrisalez' chest. The officer died nine days later.

Petitioner Herrera was arrested a few days after the
shootings and charged with the capital murder of both
Carrisalez and Rucker. He was tried and found guilty of
the capital murder of Carrisalez in January 1982, and
sentenced to death. In July 1982, petitioner pleaded
guilty to the murder of Rucker.

At petitioner's trial for the murder of Carrisalez, Hernandez, who had witnessed Carrisalez' slaying from the
officer's patrol car, identified petitioner as the person who
had wielded the gun. A declaration by Officer Carrisalez
to the same effect, made while he was in the hospital,
was also admitted. Through a license plate check, it was
shown that the speeding car involved in Carrisalez'
murder was registered to petitioner's "live in" girlfriend.
Petitioner was known to drive this car, and he had a set
of keys to the car in his pants pocket when he was
arrested. Hernandez identified the car as the vehicle from
which the murderer had emerged to fire the fatal shot.
He also testified that there had been only one person in
the car that night.

The evidence showed that Herrera's Social Security card
had been found alongside Rucker's patrol car on the night
he was killed. Splatters of blood on the car identified as
the vehicle involved in the shootings, and on petitioner's
blue jeans and wallet were identified as type A blood--the
same type which Rucker had. (Herrera has type O blood.)
Similar evidence with respect to strands of hair found in
the car indicated that the hair was Rucker's and not
Herrera's. A handwritten letter was also found on the
person of petitioner when he was arrested, which strongly
implied that he had killed Ru cker.
[n.1]

Petitioner appealed his conviction and sentence, arguing,
among other things, that Hernandez' and Carrisalez'
identifications were unreliable and improperly admitted.
The Texas Court of Criminal Appeals affirmed, Herrera
v. State, 682 S. W. 2d 313 (1984), and we denied certiorari, 471 U.S. 1131 (1985). Petitioner's application for state
habeas relief was denied. Ex parte Herrera,No. 12,848-02 (Tex. Crim. App., Aug. 2, 1985). Petitioner
then filed a federal habeas petition, again challenging the
identifications offered against him at trial. This petition
was denied, see 904 F. 2d 944 (CA5), and we again denied
certiorari. 498 U.S. 925 (1990).

Petitioner next returned to state court and filed a
second habeas petition, raising, among other things, a
claim of "actual innocence" based on newly discovered
evidence. In support of this claim petitioner presented the
affidavits of Hector Villarreal, an attorney who had
represented petitioner's brother, Raul Herrera, Sr., and of
Juan Franco Palacious, one of Raul Sr.'s former cellmates.
Both individuals claimed that Raul Sr., who died in 1984,
had told them that he--and not petitioner--had killed
Officers Rucker and Carrisalez.
[n.2]
The State District Courtdenied this application, finding that "no evidence at trial
remotely suggest[ed] that anyone other than [petitioner]
committed the offense." Ex parte Herrera, No. 81-CR 672-C (Tex. 197th Jud. Dist., Jan. 14, 1991), ¶35. The
Texas Court of Criminal Appeals affirmed, Ex parte
Herrera, 819 S. W. 2d 528 (1991), and we denied certiorari, Herrera v. Texas, 502 U.S. ___ (1992).

In February 1992, petitioner lodged the instant habeas
petition--his second--in federal court, alleging, among
other things, that he is innocent of the murders of Rucker
and Carrisalez, and that his execution would thus violate
the Eighth and Fourteenth Amendments. In addition to
proffering the above affidavits, petitioner presented the
affidavits of Raul Herrera, Jr., Raul Sr.'s son, and Jose
Ybarra, Jr., a schoolmate of the Herrera brothers. Raul
Jr. averred that he had witnessed his father shoot Officers
Rucker and Carrisalez and petitioner was not present.
Raul Jr. was nine years old at the time of the killings.
Ybarra alleged that Raul Sr. told him one summer night
in 1983 that he had shot the two police officers.
[n.3]
Petitioner alleged that law enforcement officials were aware
of this evidence, and had withheld it in violation of Brady
v. Maryland,373 U.S. 83 (1963).

The District Court dismissed most of petitioner's claims
as an abuse of the writ. No. M 92-30 (SD Tex. Feb. 17,
1992). However, "in order to ensure that Petitioner can
assert his constitutional claims and out of a sense of
fairness and due process," the District Court granted
petitioner's request for a stay of execution so that he
could present his claim of actual innocence, along with the
Raul Jr. and Ybarra affidavits, in state court. App.38-39. Although it initially dismissed petitioner's Brady
claim on the ground that petitioner had failed to present "any evidence of withholding exculpatory material by the
prosecution," App. 37, the District Court also granted an
evidentiary hearing on this claim after reconsideration, id.,
at 54.

The Court of Appeals vacated the stay of execution.
954 F. 2d 1029 (CA5 1992). It agreed with the District
Court's initial conclusion that there was no evidentiary
basis for petitioner's Brady claim, and found disingenuous
petitioner's attempt to couch his claim of actual innocence
in Brady terms. 954 F. 2d, at 1032. Absent an accom panying constitutional violation, the Court of Appeals held
that petitioner's claim of actual innocence was not cognizable because, under Townsend v. Sain,372 U.S. 293, 317
(1963), "the existence merely of newly discovered evidence
relevant to the guilt of a state prisoner is not a ground
for relief on federal habeas corpus." See 954 F. 2d at
1034.
[n.4]
We granted certiorari, 502 U.S. ___ (1992), and
the Texas Court of Criminal Appeals stayed petitioner's
execution. We now affirm.

Petitioner asserts that the Eighth and Fourteenth
Amendments to the United States Constitution prohibit
the execution of a person who is innocent of the crime for
which he was convicted. This proposition has an elemental appeal, as would the similar proposition that the
Constitution prohibits the imprisonment of one who is
innocent of the crime for which he was convicted. After
all, the central purpose of any system of criminal justice
is to convict the guilty and free the innocent. See UnitedStates v. Nobles,422 U.S. 225, 230 (1975). But the
evidence upon which petitioner's claim of innocence rests
was not produced at his trial, but rather eight years later.
In any system of criminal justice, "innocence" or "guilt"
must be determined in some sort of a judicial proceeding.
Petitioner's showing of innocence, and indeed his
constitutional claim for relief based upon that showing,
must be evaluated in the light of the previous proceedings
in this case, which have stretched over a span of 10 years.

A person when first charged with a crime is entitled to
a presumption of innocence, and may insist that his guilt
be established beyond a reasonable doubt. In re Winship,397 U.S. 358 (1970). Other constitutional provisions also
have the effect of ensuring against the risk of convicting
an innocent person. See, e. g., Coy v. Iowa,487 U.S. 1012 (1988) (right to confront adverse witnesses); Taylor
v. Illinois,484 U.S. 400 (1988) (right to compulsory
process); Strickland v. Washington,466 U.S. 668 (1984)
(right to effective assistance of counsel); Winship,supra
(prosecution must prove guilt beyond a reasonable doubt);
Duncan v. Louisiana,391 U.S. 145 (1968) (right to jury
trial); Brady v. Maryland,373 U.S. 83 (1963) (prosecution
must disclose exculpatory evidence); Gideon v. Wainwright,372 U.S. 335 (1963) (right to assistance of counsel); In
re Murchison,349 U.S. 133, 136 (1955) (right to "fair
trial in a fair tribunal"). In capital cases, we have
required additional protections because of the nature of
the penalty at stake. See, e. g.,Beck v. Alabama,447 U.S. 625 (1980) (jury must be given option of convicting
the defendant of a lesser offense). All of these
constitutional safeguards, of course, make it more difficult
for the State to rebut and finally overturn the
presumption of innocence which attaches to every criminal
defendant. But we have also observed that "[d]ue process
does not require that every conceivable step be taken, at
whatever cost, to eliminate the possibility of convicting an
innocent person." Patterson v. New York,432 U.S. 197,208 (1977). To conclude otherwise would all but paralyze
our system for enforcement of the criminal law.

Once a defendant has been afforded a fair trial and
convicted of the offense for which he was charged, the
presumption of innocence disappears. Cf. Ross v. Moffitt,417 U.S. 600, 610 (1974) ("The purpose of the trial stage
from the State's point of view is to convert a criminal
defendant from a person presumed innocent to one found
guilty beyond a reasonable doubt"). Here, it is not
disputed that the State met its burden of proving at trial
that petitioner was guilty of the capital murder of Officer
Carrisalez beyond a reasonable doubt. Thus, in the eyes
of the law, petitioner does not come before the Court as
one who is "innocent," but on the contrary as one who has
been convicted by due process of law of two brutal murders.

Based on affidavits here filed, petitioner claims that
evidence never presented to the trial court proves him
innocent notwithstanding the verdict reached at his trial.
Such a claim is not cognizable in the state courts of
Texas. For to obtain a new trial based on newly dis covered evidence, a defendant must file a motion within
30 days after imposition or suspension of sentence. Tex.
Rule App. Proc. 31(a)(1) (1992). The Texas courts have
construed this 30-day time limit as jurisdictional. See
Beathard v. State, 767 S. W. 2d 423, 433 (Tex. Crim. App.
1989); Drew v. State, 743 S. W. 2d 207, 222-223 (Tex.
Crim. App. 1987).

Claims of actual innocence based on newly discovered
evidence have never been held to state a ground for
federal habeas relief absent an independent constitutional
violation occurring in the underlying state criminal
proceeding. Chief Justice Warren made this clear in
Townsend v. Sain,372 U.S. 293, 317 (1963) (emphasis
added):

"Where newly discovered evidence is alleged in a
habeas application, evidence which could notreasonably have been presented to the state trier of
facts, the federal court must grant an evidentiary
hearing. Of course, such evidence must bear upon the
constitutionality of the applicant's detention; the
existence merely of newly discovered evidence relevant
to the guilt of a state prisoner is not a ground for
relief on federal habeas corpus."

This rule is grounded in the principle that federal habeas
courts sit to ensure that individuals are not imprisoned
in violation of the Constitution--not to correct errors of
fact. See, e. g.,Moore v. Dempsey, 261 U.S. 86, 87-88
(1923) (Holmes, J.) ("[W]hat we have to deal with [on
habeas review] is not the petitioners' innocence or guilt
but solely the question whether their constitutional rights
have been preserved"); Hyde v. Shine, 199 U.S. 62, 84
(1905) ("[I]t is well settled that upon habeas corpus the
court will not weigh the evidence") (emphasis in original);
Ex parte Terry,128 U.S. 289, 305 (1888) ("As the writ
of habeas corpus does not perform the office of a writ of
error or an appeal, [the facts establishing guilt] cannot be
re examined or reviewed in this collateral proceeding")
(emphasis in original).

More recent authority construing federal habeas statutes
speaks in a similar vein. "Federal courts are not forums
in which to relitigate state trials." Barefoot v. Estelle, 463 U.S. 880, 887 (1983). The guilt or innocence determination in state criminal trials is "a decisive and portentous
event." Wainwright v. Sykes, 433 U.S. 72, 90 (1977). "Society's resources have been concentrated at that time
and place in order to decide, within the limits of human
fallibility, the question of guilt or innocence of one of its
citizens." Ibid. Few rulings would be more disruptive of
our federal system than to provide for federal habeas
review of free standing claims of actual innocence.

Our decision in Jackson v. Virginia, 443 U.S. 307
(1979), comes as close to authorizing evidentiary review
of a state court conviction on federal habeas as any of ourcases. There, we held that a federal habeas court may
review a claim that the evidence adduced at a state trial
was not sufficient to convict a criminal defendant beyond
a reasonable doubt. But in so holding, we emphasized:

"[T]his inquiry does not require a court to `ask itself
whether it believes that the evidence at the trial
established guilt beyond a reasonable doubt.' Instead,
the relevant question is whether, after viewing the
evidence in the light most favorable to the prosecution, any rational trier of fact could have found the
essential elements of the crime beyond a reasonable
doubt. This familiar standard gives full play to the
responsibility of the trier of fact fairly to resolve
conflicts in the testimony, to weigh the evidence, and
to draw reasonable inferences from basic facts to
ultimate facts." Id., at 318-319 (citations omitted)
(emphasis in original).

We specifically noted that "the standard announced . . .
does not permit a court to make its own subjective
determination of guilt or innocence." Id., at 320, n. 13.

The type of federal habeas review sought by petitioner
here is different in critical respects than that authorized
by Jackson. First, the Jackson inquiry is aimed at
determining whether there has been an independent
constitutional violation--i.e., a conviction based on evidence that fails to meet the Winship standard. Thus,
federal habeas courts act in their historic capacity--to
assure that the habeas petitioner is not being held in
violation of his or her federal constitutional rights.
Second, the sufficiency of the evidence review authorized
by Jackson is limited to "record evidence." 443 U. S., at
318. Jackson does not extend to nonrecord evidence,
including newly discovered evidence. Finally, the Jackson
inquiry does not focus on whether the trier of fact made
the correct guilt or innocence determination, but rather
whether it made a rational decision to convict or acquit.

Petitioner is understandably imprecise in describing the
sort of federal relief to which a suitable showing of actual
innocence would entitle him. In his brief he states that
the federal habeas court should have "an important initial
opportunity to hear the evidence and resolve the merits
of Petitioner's claim." Brief for Petitioner 42. Acceptance
of this view would presumably require the habeas court
to hear testimony from the witnesses who testified at trial
as well as those who made the statements in the affidavits which petitioner has presented, and to determine
anew whether or not petitioner is guilty of the murder of
Officer Carrisalez. Indeed, the dissent's approach differs
little from that hypothesized here.

The dissent would place the burden on petitioner to
show that he is "probably" innocent. Post, at 14-15.
Although petitioner would not be entitled to discovery "as
a matter of right," the District Court would retain its "discretion to order discovery . . . when it would help the
court make a reliable determination with respect to the
prisoner's claim." Post, at 16. And although the District
Court would not be required to hear testimony from the
witnesses who testified at trial or the affiants upon whom
petitioner relies, it would allow the District Court to do
so "if the petition warrants a hearing." Post, at 16. At
the end of the day, the dissent would have the District
Court "make a case by case determination about the
reliability of newly discovered evidence under the
circumstances," and then "weigh the evidence in favor of
the prisoner against the evidence of his guilt." Post, at15.

The dissent fails to articulate the relief that would be
available if petitioner were to meets its "probable
innocence" standard. Would it be commutation of
petitioner's death sentence, new trial, or unconditional
release from imprisonment? The typical relief granted in
federal habeas corpus is a conditional order of release
unless the State elects to retry the successful habeaspetitioner, or in a capital case a similar conditional order
vacating the death sentence. Were petitioner to satisfy
the dissent's "probable innocence" standard, therefore, the
District Court would presumably be required to grant a
conditional order of relief, which would in effect require
the State to retry petitioner 10 years after his first trial,
not because of any constitutional violation which had
occurred at the first trial, but simply because of a belief
that in light of petitioner's new found evidence a jury
might find him not guilty at a second trial.

Yet there is no guarantee that the guilt or innocence
determination would be any more exact. To the contrary,
the passage of time only diminishes the reliability of
criminal adjudications. See McCleskey v. Zant, 499 U.S. ___ (1991) (slip op., at 22) ("[W]hen a habeas petitioner
succeeds in obtaining a new trial, the `erosion of memory
and dispersion of witnesses that occur with the passage
of time' prejudice the government and diminish the
chances of a reliable criminal adjudication") (quoting
Kuhlmann v. Wilson,477 U.S. 436, 453 (1986) (plurality
opinion) (internal quotation marks omitted; citation
omitted)); United States v. Smith,331 U.S. 469, 476
(1947). Under the dissent's approach, the District Court
would be placed in the even more difficult position of
having to weigh the probative value of "hot" and "cold"
evidence on petitioner's guilt or innocence.

This is not to say that our habeas jurisprudence casts
a blind eye towards innocence. In a series of cases
culminating with Sawyer v. Whitley, 505 U.S. ___ (1992), decided last Term, we have held that a petitioner
otherwise subject to defenses of abusive or successive use
of the writ may have his federal constitutional claim
considered on the merits if he makes a proper showing of
actual innocence. This rule, or fundamental miscarriage
of justice exception, is grounded in the "equitablediscretion" of habeas courts to see that federalconstitutional errors do not result in the incarceration of

innocent persons. See McCleskey, supra, at ___ (slip op.,
at 33). But this body of our habeas jurisprudence makes
clear that a claim of "actual innocence" is not itself a
constitutional claim, but instead a gateway through which
a habeas petitioner must pass to have his otherwise
barred constitutional claim considered on the merits.

Petitioner in this case is simply not entitled to habeas
relief based on the reasoning of this line of cases. For he
does not seek excusal of a procedural error so that he
may bring an independent constitutional claim challenging
his conviction or sentence, but rather argues that he is
entitled to habeas relief because newly discovered evidence
shows that his conviction is factually incorrect. The
fundamental miscarriage of justice exception is available "only where the prisoner supplements his constitutional
claim with a colorable showing of factual innocence."
Kuhlmann, supra, at 454 (emphasis added). We have
never held that it extends to free standing claims of actual
innocence. Therefore, the exception is inapplicable here.

Petitioner asserts that this case is different because he
has been sentenced to death. But we have "refused to
hold that the fact that a death sentence has been imposed
requires a different standard of review on federal habeas
corpus." Murray v. Giarratano,492 U.S. 1, 9 (1989)
(plurality opinion). We have, of course, held that the
Eighth Amendment requires increased reliability of the
process by which capital punishment may be imposed.
See, e. g.,McKoy v. North Carolina,494 U.S. 433 (1990)
(unanimity requirement impermissibly limits jurors'
consideration of mitigating evidence); Eddings v.
Oklahoma,455 U.S. 105 (1982) (jury must be allowed to
consider all of a capital defendant's mitigating character
evidence); Lockett v. Ohio,438 U.S. 586, 604 (1978)
(plurality opinion) (same). But petitioner's claim does not
fit well into the doctrine of these cases, since, as we have
pointed out, it is far from clear that a second trial 10

years after the first trial would produce a more reliable
result.

Perhaps mindful of this, petitioner urges not that he
necessarily receive a new trial, but that his death sentence simply be vacated if a federal habeas court deems
that a satisfactory showing of "actual innocence" has been
made. Tr. of Oral Arg. 19-20. But such a result is
scarcely logical; petitioner's claim is not that some error
was made in imposing a capital sentence upon him, but
that a fundamental error was made in finding him guilty
of the underlying murder in the first place. It would be
a rather strange jurisprudence, in these circumstances,
which held that under our Constitution he could not be
executed, but that he could spend the rest of his life in
prison.

Petitioner argues that our decision in Ford v. Wainwright,477 U.S. 399 (1986), supports his position. The
plurality in Ford held that, because the Eighth Amendment prohibits the execution of insane persons, certain
procedural protections inhere in the sanity determination. "[I]f the Constitution renders the fact or timing of his
execution contingent upon establishment of a further fact,"
Justice Marshall wrote, "then that fact must be determined with the high regard for truth that befits a decision
affecting the life or death of a human being." Id., at 411.
Because the Florida scheme for determining the sanity of
persons sentenced to death failed "to achieve even the
minimal degree of reliability," id., at 413, the plurality
concluded that Ford was entitled to an evidentiary hearing
on his sanity before the District Court.

Unlike petitioner here, Ford did not challenge the
validity of his conviction. Rather, he challenged the
constitutionality of his death sentence in view of his claim
of insanity. Because Ford's claim went to a matter of
punishment--not guilt--it was properly examined within
the purview of the Eighth Amendment. Moreover, unlike

the question of guilt or innocence, which becomes more
uncertain with time for evidentiary reasons, the issue of
sanity is properly considered in proximity to the execution.
Finally, unlike the sanity determination under the Florida
scheme at issue in Ford, the guilt or innocence determination in our system of criminal justice is made "with the
high regard for truth that befits a decision affecting the
life or death of a human being." Id., at 411.

Petitioner also relies on Johnson v. Mississippi,486 U.S. 578 (1988), where we held that the Eighth Amendment requires reexamination of a death sentence based in
part on a prior felony conviction which was set aside in
the rendering State after the capital sentence was imposed. There, the State insisted that it was too late in
the day to raise this point. But we pointed out that the
Mississippi Supreme Court had previously considered
similar claims by writ of error coram nobis. Thus, there
was no need to override state law relating to newly
discovered evidence in order to consider Johnson's claim
on the merits. Here, there is no doubt that petitioner
seeks additional process--an evidentiary hearing on his
claim of "actual innocence" based on newly discovered
evidence--which is not available under Texas law more
than 30 days after imposition or suspension of sentence.
Tex. Rule App. Proc. 31(a)(1) (1992).
[n.5]

Alternatively, petitioner invokes the Fourteenth
Amendment's guarantee of due process of law in supportof his claim that his showing of actual innocence entitles
him to a new trial, or at least to a vacation of his death
sentence.
[n.6]
"[B]ecause the States have considerable expertise in matters of criminal procedure and the criminal
process is grounded in centuries of common law tradition,"
we have "exercis[ed] substantial deference to legislative
judgments in this area." Medina v. California, 505 U.S. ___ (1992) (slip op., at 7-8). Thus, we have found
criminal process lacking only where it " `offends some
principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.' "
Ibid. (quoting Patterson v. New York,432 U.S. 197, 202
(1977)). "Historical practice is probative of whether a
procedural rule can be characterized as fundamental."
505 U. S., at

.

The Constitution itself, of course, makes no mention of
new trials. New trials in criminal cases were not granted
in England until the end of the 17th century. And even
then, they were available only in misdemeanor cases,
though the writ of error coram nobis was available for
some errors of fact in felony cases. Orfield, New Trial in

Federal Criminal Cases, 2 Vill. L. Rev. 293, 304 (1957).
The First Congress provided for new trials for "reasons for
which new trials have usually been granted in courts of
law." Act of Sept. 24, 1789, ch. 20, §17, 1 Stat. 83. This
rule was early held to extend to criminal cases. See
Sparf and Hansen v. United States,156 U.S. 51, 175
(1895) (Gray, J., dissenting) (citing cases). One of the
grounds upon which new trials were granted was newly
discovered evidence. See F. Wharton, Criminal Pleading
and Practice §§854-874, pp. 584-592 (8th ed. 1880).

The early federal cases adhere to the common law rule
that a new trial may be granted only during the term of
court in which the final judgment was entered. See, e. g.,United States v. Mayer,235 U.S. 55, 67 (1914); United
States v. Simmons, 27 F. Cas. 1080, (No. 16,289)
(CCEDNY 1878). Otherwise, "the court at a subsequent
term has power to correct inaccuracies in mere matters
of form, or clerical errors." 235 U. S., at 67. In 1934,
this Court departed from the common law rule and
adopted a time limit--60 days after final judgment--for
filing new trial motions based on newly discovered evidence. Rule II(3), Criminal Rules of Practice and Procedure, 292 U.S. 659, 662. Four years later, we amended
Rule II(3) to allow such motions in capital cases "at any
time" before the execution took place. 304 U.S. 592, 592
(1938) (codified at 18 U.S.C. § 688 (1940)).

There ensued a debate as to whether this Court should
abolish the time limit for filing new trial motions based
on newly discovered evidence to prevent a miscarriage of
justice, or retain a time limit even in capital cases to
promote finality. See Orfield, supra, at 299-304. In
1945, we set a two-year time limit for filing new trial
motions based on newly discovered evidence and abolished
the exception for capital cases. Rule 33, Federal Rules of
Criminal Procedure, 327 U.S. 821, 855-856 ("A motion
for new trial based on the ground of newly discovered
evidence may be made only before or within two yearsafter final judgment").
[n.7]
We have strictly construed the
Rule 33 time limits. Cf. United States v. Smith,331 U.S. 469, 473 (1947). And the Rule's treatment of new
trials based on newly discovered evidence has not changed
since its adoption.

The American Colonies adopted the English common law
on new trials. Riddell, New Trial in Present Practice, 27
Yale L. J. 353, 360 (1917). Thus, where new trials were
available, motions for such relief typically had to be filed
before the expiration of the term during which the trial
was held. H. Underhill, Criminal Evidence 579, n. 1
(1898); J. Bassett, Criminal Pleading and Practice 313
(1885). Over time, many States enacted statutes providing for new trials in all types of cases. Some States also
extended the time period for filing new trial motions
beyond the term of court, but most States required that
such motions be made within a few days after the verdict
was rendered or before the judgment was entered. See
American Law Institute Code of Criminal Procedure
1040-1042 (Official Draft 1931) (reviewing contemporary
new trials rules).

The practice in the States today, while of limited
relevance to our historical inquiry, is divergent. Texas isone of 17 States that requires a new trial motion based
on newly discovered evidence to be made within 60 days
of judgment.
[n.8]
One State adheres to the common law rule
and requires that such a motion be filed during the term
in which judgment was rendered.
[n.9]
Eighteen jurisdictions
have time limits ranging between 1 and 3 years, with 10
States and the District of Columbia following the 2-year
federal time limit.
[n.10]
Only 15 States allow a new trial
motion based on newly discovered evidence to be filed
more than 3 years after conviction. Of these States, 4
have waivable time limits of less than 120 days, 2 havewaivable time limits of more than 120 days, and 9 States
have no time limits.
[n.11]

In light of the historical availability of new trials, our
own amendments to Rule 33, and the contemporary
practice in the States, we cannot say that Texas' refusal
to entertain petitioner's newly discovered evidence eight
years after his conviction transgresses a principle of
fundamental fairness "rooted in the traditions and conscience of our people." Patterson v. New York, 432 U. S.,
at 202 (internal quotation marks and citations omitted).
This is not to say, however, that petitioner is left without
a forum to raise his actual innocence claim. For under
Texas law, petitioner may file a request for executive
clemency. See Tex. Const., Art. IV., §11; Tex. Code Crim.
Proc. Ann., Art. 48.01 (Vernon 1979). Clemency
[n.12]
is
deeply rooted in our Anglo American tradition of law, and
is the historic remedy for preventing miscarriages of
justice where judicial process has been exhausted.
[n.13]

In England, the clemency power was vested in the
Crown and can be traced back to the 700's. W. Humbert,
The Pardoning Power of the President 9 (1941). Blackstone thought this "one of the great advantages of monarchy in general, above any other form of government; that
there is a magistrate, who has it in his power to extend
mercy, wherever he thinks it is deserved: holding a court
of equity in his own breast, to soften the rigour of the
general law, in such criminal cases as merit an exemption
from punishment." 4 W. Blackstone, Commentaries *397.
Clemency provided the principal avenue of relief for
individuals convicted of criminal offenses--most of which
were capital--because there was no right of appeal until
1907. 1 L. Radzinowicz, A History of English Criminal
Law 122 (1948). It was the only means by which one
could challenge his conviction on the ground of innocence.
United States Dept. of Justice, 3 Attorney General's
Survey of Release Procedures 73 (1939).

Our Constitution adopts the British model and gives to
the President the "Power to grant Reprieves and Pardons
for Offences against the United States." Art. II, §2, cl. 1.
In United States v. Wilson, 7 Pet. 150, 160-161 (1833),
Chief Justice Marshall expounded on the President's
pardon power:

"As this power had been exercised from time immemorial by the executive of that nation whose language
is our language, and to whose judicial institutions
ours bears a close resemblance; we adopt their principles respecting the operation and effect of a pardon,
and look into their books for the rules prescribing the
manner in which it is to be used by the person who
would avail himself of it.

"A pardon is an act of grace, proceeding from the
power entrusted with the execution of the laws, which
exempts the individual, on whom it is bestowed, from
the punishment the law inflicts for a crime he has
committed. It is the private, though official act of the
executive magistrate, delivered to the individual for
whose benefit it is intended, and not communicated
officially to the court. It is a constituent part of the
judicial system, that the judge sees only with judicial
eyes, and knows nothing respecting any particular
case, of which he is not informed judicially. A private
deed, not communicated to him, whatever may be its
character, whether a pardon or release, is totally
unknown and cannot be acted on. The looseness
which would be introduced into judicial proceedings,
would prove fatal to the great principles of justice, if
the judge might notice and act upon facts not brought
regularly into the cause. Such a proceeding, in
ordinary cases, would subvert the best established
principles, and overturn those rules which have been
settled by the wisdom of ages."

See also Ex parte Garland, 4 Wall. 333, 380-381 (1867);
The Federalist No. 74, pp. 447-449 (C. Rossiter ed. 1961)
(A. Hamilton) ("The criminal code of every country
partakes so much of necessary severity that without an
easy access to exceptions in favor of unfortunate guilt,

justice would wear a countenance too sanguinary and
cruel").

Of course, although the Constitution vests in the
President a pardon power, it does not require the States
to enact a clemency mechanism. Yet since the British
Colonies were founded, clemency has been available in
America. C. Jensen, The Pardoning Power in the
American States 3-4 (1922). The original States were
reluctant to vest the clemency power in the executive.
And although this power has gravitated toward the
executive over time, several States have split the clemency
power between the Governor and an advisory board
selected by the legislature. See Survey of Release
Procedures, supra, at 91-98. Today, all 36 States that
authorize capital punishment have constitutional or statu

Executive clemency has provided the "fail safe" in our
criminal justice system. K. Moore, Pardons: Justice,
Mercy, and the Public Interest 131 (1989). It is an
unalterable fact that our judicial system, like the human
beings who administer it, is fallible. But history is
replete with examples of wrongfully convicted persons who
have been pardoned in the wake of after discovered
evidence establishing their innocence. In his classic work,
Professor Edwin Borchard compiled 65 cases in which it
was later determined that individuals had been wrongfully
convicted of crimes. Clemency provided the relief
mechanism in 47 of these cases; the remaining cases
ended in judgments of acquittals after new trials.
E. Borchard, Convicting the Innocent (1932). Recent
authority confirms that over the past century clemency
has been exercised frequently in capital cases in which
demonstrations of "actual innocence" have been made. See
M. Radelet, H. Bedau, & C. Putnam, In Spite of Innocence
282-356 (1992).
[n.15]

In Texas, the Governor has the power, upon the recommendation of a majority of the Board of Pardons and
Paroles, to grant clemency. Tex. Const., Art. IV, §11; Tex.
Code Crim. Proc. Ann.; Art. 48.01 (Vernon 1979). The
board's consideration is triggered upon request of the
individual sentenced to death, his or her representative,
or the Governor herself. In capital cases, a request may
be made for a full pardon, Tex. Admin. Code, Tit. 37,
§143.1 (West Supp. 1992), a commutation of death sentence to life imprisonment or appropriate maximum
penalty, §143.57, or a reprieve of execution, §143.43. The
Governor has the sole authority to grant one reprieve in
any capital case not exceeding 30 days. §143.41(a).

The Texas clemency procedures contain specific guidelines for pardons on the ground of innocence. The board
will entertain applications for a recommendation of full
pardon because of innocence upon receipt of the following: "(1) a written unanimous recommendation of the current
trial officials of the court of conviction; and/or (2) a
certified order or judgment of a court having jurisdiction
accompanied by certified copy of the findings of fact (if
any); and (3) affidavits of witnesses upon which the
finding of innocence is based." §143.2. In this case,
petitioner has apparently sought a 30-day reprieve from
the Governor, but has yet to apply for a pardon, or even
a commutation, on the ground of innocence or otherwise.
Tr. of Oral Arg. 7, 34.

As the foregoing discussion illustrates, in state criminal
proceedings the trial is the paramount event for
determining the guilt or innocence of the defendant.
Federal habeas review of state convictions has
traditionally been limited to claims of constitutionalviolations occurring in the course of the underlying state
criminal proceedings. Our federal habeas cases have
treated claims of "actual innocence," not as an
independent constitutional claim, but as a basis upon
which a habeas petitioner may have an independent
constitutional claim considered on the merits, even though
his habeas petition would otherwise be regarded as
successive or abusive. History shows that the traditional
remedy for claims of innocence based on new evidence,
discovered too late in the day to file a new trial motion,
has been executive clemency.

We may assume, for the sake of argument in deciding
this case, that in a capital case a truly persuasive demonstration of "actual innocence" made after trial would
render the execution of a defendant unconstitutional, and
warrant federal habeas relief if there were no state
avenue open to process such a claim. But because of the
very disruptive effect that entertaining claims of actual
innocence would have on the need for finality in capital
cases, and the enormous burden that having to retry cases
based on often stale evidence would place on the States,
the threshold showing for such an assumed right would
necessarily be extraordinarily high. The showing made
by petitioner in this case falls far short of any such
threshold.

Petitioner's newly discovered evidence consists of
affidavits. In the new trial context, motions based solely
upon affidavits are disfavored because the affiants'
statements are obtained without the benefit of cross examination and an opportunity to make credibility
determinations. See Orfield, 2 Vill. L. Rev., at 333.
Petitioner's affidavits are particularly suspect in this
regard because, with the exception of Raul Herrera, Jr.'s,
affidavit, they consist of hearsay. Likewise, in reviewing
petitioner's new evidence, we are mindful that defendants
often abuse new trial motions "as a method of delaying
enforcement of just sentences." United States v. Johnson,327 U.S. 106, 112 (1946). Although we are not presented
with a new trial motion per se, we believe the likelihood
of abuse is as great--or greater--here.

The affidavits filed in this habeas proceeding were given
over eight years after petitioner's trial. No satisfactory
explanation has been given as to why the affiants waited
until the 11th hour--and, indeed, until after the alleged
perpetrator of the murders himself was dead--to make
their statements. Cf. Taylor v. Illinois, 484 U.S. 400,
414 (1988) ("[I]t is . . . reasonable to presume that there
is something suspect about a defense witness who is not
identified until after the 11th hour has passed"). Equally
troubling, no explanation has been offered as to why
petitioner, by hypothesis an innocent man, pleaded guilty
to the murder of Rucker.

Moreover, the affidavits themselves contain inconsistencies, and therefore fail to provide a convincing account of
what took place on the night Officers Rucker and Carrisalez were killed. For instance, the affidavit of Raul Jr.,
who was nine years old at the time, indicates that there
were three people in the speeding car from which the
murderer emerged, whereas Hector Villarreal attested that
Raul Sr. told him that there were two people in the car
that night. Of course, Hernandez testified at petitioner's
trial that the murderer was the only occupant of the car.
The affidavits also conflict as to the direction in which the
vehicle was heading when the murders took place, and
petitioner's whereabouts on the night of the killings.

Finally, the affidavits must be considered in light of the
proof of petitioner's guilt at trial--proof which included
two eyewitness identifications, numerous pieces of circumstantial evidence, and a handwritten letter in which
petitioner apologized for killing the officers and offered to
turn himself in under certain conditions. See supra, at
2-3, and n. 1. That proof, even when considered alongside petitioner's belated affidavits, points strongly to
petitioner's guilt.

This is not to say that petitioner's affidavits are without
probative value. Had this sort of testimony been offered
at trial, it could have been weighed by the jury, along
with the evidence offered by the State and petitioner, in
deliberating upon its verdict. Since the statements in the
affidavits contradict the evidence received at trial, the jury
would have had to decide important issues of credibility.
But coming 10 years after petitioner's trial, this showing
of innocence falls far short of that which would have to
be made in order to trigger the sort of constitutional claim
which we have assumed, arguendo, to exist.

The judgment of the Court of Appeals is

Affirmed.

Notes

The letter read: "To whom it may concern: I am terribly sorry for those
I have brought grief to their lives. Who knows why? We cannot change
the future's problems with problems from the past. What I did was for
a cause and purpose. One law runs others, and in the world we live in,
that's the way it is.

"I'm not a tormented person. . . . I believe in the law. What would it
be without this [sic] men that risk their lives for others, and that's what
they should be doing--protecting life, property, and the pursuit of
happiness. Sometimes, the law gets too involved with other things that
profit them. The most laws that they make for people to break them, in
other words, to encourage crime.

"What happened to Rucker was for a certain reason. I knew him as
Mike Tatum. He was in my business, and he violated some of its laws
and suffered the penalty, like the one you have for me when the time
comes.

"My personal life, which has been a conspiracy since my high school
days, has nothing to do with what has happened. The other officer that
became part of our lives, me and Rucker's (Tatum), that night had not
to do in this [sic]. He was out to do what he had to do, protect, but that's
life. There's a lot of us that wear different faces in lives every day, and
that is what causes problems for all. [Unintelligible word].

"You have wrote all you want of my life, but think about yours, also.
[Signed Leonel Herrera].

"I have tapes and pictures to prove what I have said. I will prove my
side if you accept to listen. You [unintelligible word] freedom of speech,
even a criminal has that right. I will present myself if this is read word
for word over the media, I will turn myself in; if not, don't have millions
of men out there working just on me while others--robbers, rapists, orburglars--are taking advantage of the law's time. Excuse my spelling
and writing. It's hard at times like this." App. to Brief for United States
as Amicus Curiae 3a-4a.

2
Villarreal's affidavit is dated December 11, 1990. He attested that
while he was representing Raul Sr. on a charge of attempted murder in
1984, Raul Sr. had told him that he, petitioner, their father, Officer
Rucker, and the Hidalgo County Sheriff were involved in a drug trafficking scheme; that he was the one who had shot Officers Rucker and
Carrisalez; that he didn't tell anyone about this because he thought
petitioner would be acquitted; and that after petitioner was convicted and
sentenced to death, he began blackmailing the Hidalgo County Sheriff.
According to Villarreal, Raul Sr. was killed by Jose Lopez, who worked
with the sheriff on drug trafficking matters and was present when Raul
Sr. murdered Rucker and Carrisalez, to silence him.

Palacious' affidavit is dated December 10, 1990. He attested that while
he and Raul Sr. shared a cell together in the Hidalgo County jail in 1984,Raul Sr. told him that he had shot Rucker and Carrisalez.

3
Raul Jr.'s affidavit is dated January 29, 1992. Ybarra's affidavit is
dated January 9, 1991. It was initially submitted with Petitioner's Reply
to State's Brief in Response to Petitioner's Petition for Writ of Habeas
Corpus filed January 18, 1991, in the Texas Court of Criminal Appeals.

4
After the Court of Appeals vacated the stay of execution, petitioner
attached a new affidavit by Raul Jr. to his Petition for Rehearing, which
was denied. The affidavit alleges that during petitioner's trial, various
law enforcement officials and the Hidalgo County Sheriff told Raul Jr. not
to say what happened on the night of the shootings and threatened his
family.

5
The dissent relies on Beck v. Alabama, 447 U.S. 625 (1980), for the
proposition that, "at least in capital cases, the Eighth Amendment
requires more than reliability in sentencing. It also mandates a reliable
determination of guilt." Post, at 6. To the extent Beck rests on Eighth
Amendment grounds, it simply emphasizes the importance of ensuring
the reliability of the guilt determination in capital cases in the first
instance. We have difficulty extending this principle to hold that a
capital defendant who has been afforded a full and fair trial may
challenge his conviction on federal habeas based on after discovered
evidence.

6
The dissent takes us to task for examining petitioner's Fourteenth
Amendment claim in terms of procedural rather than substantive due
process. Because "[e]xecution of an innocent person is the ultimate
`arbitrary impositio[n],' " post, at 9, quoting Planned Parenthood of
Southeastern Pennsylvania v. Casey, 505 U. S. -- , -- (1992) (slip op., at
6) (internal quotation marks omitted), the dissent concludes that "petitioner may raise a substantive due process challenge to his
punishment on the ground that he is actually innocent." Post, at 8. But
the dissent puts the cart before the horse. For its due process analysis
rests on the assumption that petitioner is in fact innocent. However, as
we have discussed, petitioner does not come before this Court as an
innocent man, but rather as one who has been convicted by due process
of law of two capital murders. The question before us, then, is not
whether due process prohibits the execution of an innocent person, but
rather whether it entitles petitioner to judicial review of his "actual
innocence" claim. This issue is properly analyzed only in terms of
procedural due process.

7
In response to the second preliminary draft of the Federal Rules of
Criminal Procedure, Chief Justice Harlan Stone forwarded a memorandum on behalf of the Court to the Rules Advisory Committee with various
comments and suggestions, including the following: "It is suggested that
there should be a definite time limit within which motions for new trial
based on newly discovered evidence should be made, unless the trial court
in its discretion, for good cause shown, allows the motion to be filed. Is
it not desirable that at some point of time further consideration of
criminal cases by the court should be at an end, after which appeals
should be made to Executive clemency alone?" 7 Drafting History of the
Federal Rules of Criminal Procedure 3, 7 (M. Wilken & N. Triffin eds.
1991) (responding to proposed Rule 35). As noted above, we eventually
rejected the adoption of a flexible time limit for new trial motions, opting
instead for a strict two year time limit.

12
The term "clemency" refers not only to full or conditional pardons, but
also commutations, remissions of fines, and reprieves. See Kobil, The
Quality of Mercy Strained: Wresting the Pardoning Power from the King,
69 Tex. L. Rev. 569, 575-578 (1991).

13
The dissent relies on the plurality opinion in Ford v. Wainwright, 477 U.S. 399 (1986), to support the proposition that "[t]he vindication of
rights guaranteed by the Constitution has never been made to turn onthe unreviewable discretion of an executive official or administrative
tribunal." Post, at 11. But that case is inapposite insofar as it pertains
to our discussion of clemency here. The Ford plurality held that Florida's
procedures for entertaining post-trial claims of insanity, which vested the
sanity determination entirely within the executive branch, were "inadequate to preclude federal redetermination of the constitutional issue [of
Ford's sanity]." 477 U. S., at 416. Unlike Ford's claim of insanity, which
had never been presented in a judicial proceeding, petitioner's claim of "actual innocence" comes 10 years after he was adjudged guilty beyond
a reasonable doubt after a full and fair trial. As the following discussion
indicates, it is clear that clemency has provided the historic mechanism
for obtaining relief in such circumstances.

15
The dissent points to one study concluding that 23 innocent persons
have been executed in the United States this century as support for the
proposition that clemency requests by persons believed to be innocent are
not always granted. See post, at 2, n. 1 (citing Bedau & Radelet,
Miscarriages of Justice in Potentially Capital Cases, 40 Stan. L. Rev. 21
(1987)). Although we do not doubt that clemency--like the criminal

justice system itself--is fallible, we note that scholars have taken issue
with this study. See Comment, Protecting the Innocent: A Response to
the Bedau Radelet Study, 41 Stan. L. Rev. 121 (1988).